HYPERION

Chaotic rotation at its best

Hyperion orbits Saturn outside the orbit of Titan at a distance of 1.5 million km from Saturn. It is a strange world indeed, sort of an irregularly shaped hamburger with the longest edge being about 350 km. Hyperion makes one trip around Saturn in about 79 days. About is as good as one can get when describing this moon's motion: Hyperion has the most bizarre motion in the solar system!

Hyperion literally "tumbles" around chaotically in its orbit. It is tugged by the gravitational pull of both Saturn and Titan. Because of this, the moon changes both its rotational speed and its axis of rotation. Astronomers call this "chaotic rotation" and Hyperion tumbles around at random in its orbit, never repeating itself!

With a density of 1.2 g/cm3 Hyperion is composed of water ice mixed with dust. It is darker than the other surrounding moons. Hyperion is also heavily cratered, and it has been theorized by some astronomers that it may have been an off center impact that added to Hyperion's chaotic orbit.